Edge trimming shears for rolled metal sheets with cross-knives for severing the edge strips

ABSTRACT

A straight-knife edge trimming shears more particularly suitable for opposite mounting in shearing lines for cutting thick sheets whose cross-knife for severing the edge strips still connected to the sheet after the cutting by the edge trimming knife has an independent drive and starts its cutting action after the edge trimming knife mounted ahead of the cross-knife.

United States Patent Hamacher [54] EDGE TRIMIVIING SHEARS FOR ROLLED METAL SHEETS WITH CROSS-KN IVES FOR SEVERING THE EDGE STRIPS [72] Inventor: Paul Friedrich l-lamacher, St. lngben (Saar), Germany [73] Assignee: Mueller 8: Neumann G.m.b.H., St. lngbert (Saar), Germany [22] Filed: Feb. 16, 1970 (21] Appl. No.: 1 1,372

[30] Foreign Application Priority Data Feb. 15, 1969 Germany ..P 19 07 777.9

[52] US. Cl ..83/513, 83/255, 83/404, 83/602, 83/923 [51] Int. Cl. ..B26d 9/00, B23d 17/04 [58] Field of Search ..83l923, 602, 605, 606, 408, 83/404, 255, 598, 607-609, 513

[ 1 June 6, 1972 [56] References Cited UNITED STATES PATENTS 3,492,898 2/1970 Benz 83/923 3,392,615 7/ 1968 Rosskath.. .83/607 X Norrie Huston ..83/923 X Primary Examiner-James M. Meister Attorney-John J. Dennemeyer s7 5 ABSTRACT A straight-knife edge trimming shears more particularly suitable for opposite mounting in shearing lines for cutting thick sheets whose cross-knife for severing the edge strips still connected to the sheet after the cutting by the edge trimming knife has an independent drive and starts its cutting action after the edge trimming knife mounted ahead of the crossknife.

2 Claims, 3 Drawing Figures PATENTEDJUN 6 I872 3.667, 335

EDGE TRIMMING SHEARS FOR ROLLED NIETAL SHEETS WITH CROSS-KNIVES FOR SEVERING THE EDGE STRIPS The invention relates to edge trimming shears for rolled cross-knife forms with the horizontal an angle of over 90. For

metal sheets having a pair of straight knives for trimming the sheet edge and cross-knives for severing the edge strips already cut from the sheet by the straight knives wherein the upper cross-knife has an independent drive and the cutting edge of the lower cross-knife is located on a lower level than the cutting edge of the stationary lower straight knife. The edge trimming shears described herein are of the type having a pair of cross-knives arranged at the output side for severing the edge strips that have been cut in the preceding trimming cut, as disclosed for example in French Pat. No. 1,392,140 and in German Utility Model Pat. No. 1,980,004.

The known edge trimming shears having a pair of crossknives at the output side are of similar construction in that the moving upper cross-knife must be guided as closely as possible past the trimmed sheet edge in order to push the cut strips still clinging to the'sheet downwardly against the lower crossknife, which requires an exact setting of the upper cross-knife after each knife change. In case the cross-knife is set too closely toward the sheet it can produce damage to the sheet edge. In case it is set too short its cutting edge does not overlap the edge strip in its entire width. Even in the case where the upper cross-knife is properly set the trimming cut may be adversely affected in the event that a narrow edge strip is twisted and turns partly under the trimmed sheet. These problems are also not solved by making the upper cross-knife movable relative to the upper straight knife and by giving it an independent drive, which is also already known for the lower cross-knife, and which has the purpose of providing a quick release for the advancement of the sheet.

These difficulties are obviated according to the inventionin that the upper cross-knife is carried in the manner of a socalled alligator shears by an oscillating lever which is mounted on an oscillating shaft disposed below the cutting edge of the lower straight knife and extends approximately parallel to the straight knives. In combination with the. known feature of a lower cross-knife located below the lower straight knife it is thus obtained that the upper cross-knife which is guided with its outer cutting edge end along an arc is capable of reaching below the trimmed sheet edge, so that it can grip together with the lower cross-knife reaching under the sheet each edge strip over the entire width. In view of this it is also no longer necessary to effect such a precise setting of the upper cross-knife after a knife change in order to get past the trimmed sheet edge, because due to the position of the oscillating shaft of the oscillating lever carrying the cross-knife, a sufiiciently large interval relative to the trimmed sheet edge may be set.

The utilization of a known alligator shears for the crossknife pair of edge trimming shears presents furthermore the advantage that, as the thickness of the sheet to be trimmed increases, the cutting angle at which the upper cross-knife attacks the edge strip, increases correspondingly. This presents an advantage with respect to the force required during the cutting of an edge strip. The drive for moving the oscillating lever with the upper cross-knife is appropriately taken from the crank shaft over a connecting rod, this crank shaft actuating also the knife support for the upper straight knife.

The upper cross-knife is appropriately arranged relative to the lower cross-knife in such a way that it is disposed behind the lower cross-knife in .the advancing direction of the sheet. In the cut surface of the edge strip which is obtained after the cross-knife cut and which is located at the confronting side surface of the upper cross-knife required an independent knife retraction in the advancing direction of the sheet, in order to avoid that the upper cross-knife glides during the return stroke along the cut surface of the edge strip still clinging to the sheet. A special knife retraction for the upper cross-knife is eliminated according to the invention in that the upper crossknife is guided in a plane which deviates from the perpendicular in such a way that the confronting knife side surface of the an alligator type shears construction of the pair of cross-knives this means that the oscillating shaft of the oscillating lever is inclined downwardly in the advancing direction of the sheet. In this way an edge strip is cut in a plane which deviates slightly from the perpendicular in which, relative to the upper limitation of the cutting surface, the upper cross-knife cuts slightly behind the upper edge of the edge strip still clinging to the sheet. Since the edge strip which is still integral with the sheet at the level of the sheet is bent by the upper cross-knife down to the subjacent lower knife, it will attempt to spring back into its original position after the cut. Due to the inclination of the cutting plane of the cross-knife arrangement by a few degrees a small interval is established during the return flexing of the edge strip between its cut surface and the confronting side surface of the upper cross-knife, so that a retraction of this knife is not necessary.

The accompanying drawing illustrates edge trimming shears according to the invention with reference to an embodiment in which:

FIG. 1 is a partial elevation view,

FIG. 2 is a vertical cross-section through the cross-knife arrangement along line II-Il in FIG. 1, and

FIG. 3 is a cross-section along line III-III in FIG. 2.

The most essential parts of the edge trimming shears according to FIG. 1 are the shears stand 10 with the lower knife beam 11, the pivotable upper knife support 12 with the upper knife 13 and the cross-knife arrangement with the oscillating lever 24 for the upper cross-knife 15 at the output side and the stationary lower cross-knife 16 disposed clearly below the upper edge 17 of the lower straight knife 18.

The advancing direction of the sheet is indicated by an arrow 20. FIG. 1 shows the inclined cutting plane of the crossknife arrangement l4, l5 and 16 whereby the confronting knife surface 15a of the upper cross-knife 15 is released during the return stroke from the cutting surface of an edge strip will clinging to the sheet when the strip springs back upwardly after the cutting of a piece of the edge strip that has passed through. The severed edge strips drop on a chute which conveys the edge strips on a scrap carrier located below the shears. I

In the cross-section according to FIG., 2 a double-armed oscillating lever 24 is shown with the knife saddle 25 for the upper cross-knife 15 as well as the lower cross-knife 16. The oscillating lever is mounted on an oscillating shaft'26 which extends parallel to the straight knives 1318, but which is arranged according to FIG. 3 at an angle in the shears stand 10 more particularly inclined downwardly in the advancing direction 20 of the sheet in order to set the inclined position of the cutting plane of the cross-knives l5 and 16 shown in FIG. 1.

In view of the fact that according to the invention the oscillating shaft 26 is located below the cutting edge of the lower straight knife 18 the outermost point of the upper cross-knife 15 describes during cutting an are 27 which extends with an interval past the trimmed edge of the sheet 30. Accordingly it is also not necessary to retract the upper cross-knife 15 in the horizontal direction during the return stroke, and similarly the cutting range of the twocross-knives can extend visibly up to the'vertical projection of the trimmed sheet 30.

The rearward end of the double-arm oscillating lever 24 is bifurcated and carries a pivot stud 28 to which a connecting rod 40 is connected over a spherical sleeve 29. The connecting rod 40 is actuated by a large eccentric 42 of the crankshaft 41 and this connection is also obtained by the intennediary of a spherical sleeve 43. The eccentric 42 is so located that the upper cross-knife 15 begins to sever the edge strip 31 cut from the sheet 30 and pushed down to the level of the lower crossknife 16. The direction of rotation of the eccentric42 is indicated in FIG. 2 by an arrow. The crankshaft 41 is the main crankshaft which actuates also the pivotable knife support 12.

The operation of the edge trimming shears according to the invention takes place in the following manner:

drive of the shears is started so that the upper straight knife 13 moves downward and cuts in for an edge strip 31. As may be seen from FIG. I the cutting edge of the upper straight knife 13 is curved at the input end as this cutting edge must come out of the sheet cross-section in the lower dead center position of the knife support 12. The drives for the knife support 12 and the cross-knife 15 are offset at an angle relative to each other in such a way that the upper cross-knife 15 starts its out later than the upper straight knife 13, while cutting the edge strip 31 still during the edging trimming cut. During the return travel of the knife support 12 as well as of the oscillating shaft 24 the upper cross-knife l overtakes the upper straight knife 13 due to the considerably larger eccentricity of the eccentric 42 of the scrap knife arrangement relative to the eccenter (not shown) of the edge trimming knife drive. in this way the upper cross-knife 15 reaches quickly the upper dead center point position in which the edge strip 31 clinging to the sheet 30, although it has sprung back approximately to the level of the sheet 30, is not obstructed. When an advancing step is completed the oscillating lever 24 has already travelled through its upper dead center point position and approaches the start-cut position shown in the drawing. r

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, and my be used in other ways without departure from the scope of the invention as defined by the following claims.

I claim:

1. Edge trimming shears for rolled metal sheet having a pair of straight knives for trimming the sheet edge and cross-knives for severing the edge strips already cut from the sheet,

wherein the upper cross knife has an independent drive and the cutting edge of the lower cross-knife is disposed at a lower level than the cutting-edge of the stationary lower straight knife, the improvement consisting in that the upper crossknife (15) is carried by an oscillating lever (24) which is mounted on an oscillating shaft (26) arranged below the cutting edge of the lower straight knife (18) and inclined downwardly in the advancing direction of the sheet and extending approximately parallel to the straight knives.

2. Edge trimming shears according to claim 1 wherein the upper cross knife (15) is guided in a plane which deviates from thevertical in such a way that the confronting side surface (150) of the cross-knife forms with the horizontal an angle of over 90".

v s a a s s 

1. Edge trimming shears for rolled metal sheet having a pair of straight knives for trimming the sheet edge and cross-knives for severing the edge strips already cut from the sheet, wherein the upper cross knife has an independent drive and the cutting edge of the lower cross-knife is disposed at a lower level than the cutting edge of the stationary lower straight knife, the improvement consisting in that the upper cross-knife (15) is carried by an oscillating lever (24) which is mounted on an oscillating shaft (26) arranged below the cutting edge of the lower straight knife (18) and inclined downwardly in the advancIng direction of the sheet and extending approximately parallel to the straight knives.
 2. Edge trimming shears according to claim 1 wherein the upper cross-knife (15) is guided in a plane which deviates from the vertical in such a way that the confronting side surface (15a) of the cross-knife forms with the horizontal an angle of over 90* . 